<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      function jiecheng(n) {
        if (n <= 0) return 1
        return n * jiecheng(n - 1)
      }
      let jiecheng2 = function () {
        if (n <= 0) return 1
        return n * jiecheng(n - 1)
      }

      let jiecheng3 = new Function(
        'n',
        'if(n<=0) return 1;return n*jiecheng(n-1)'
      )
      console.log(jiecheng3(6))
    </script>
  </body>
</html>
